/* 头部 */
#head{
    width: 100%;
}
#head .wrapper{
    width: 1200px;
    height: 90px;
    margin: 0px auto; 
    /* background: #ffffff;  */
    position: relative;
}
#head .wrapper .logo img{
    float: left;
}
#head .wrapper .logo img{
    width: 241px;
    height: 81px;
}
#head .wrapper .nav{
    width: 740px;
    height: 90px;
    text-align: center;
    line-height: 90px;
    float: right;
    display: flex;
    margin-right: 150px;
}
#head .wrapper .nav li{
    width: 104px;
    height: 90px;
    line-height: 90px;
    margin: 0px 2px;
}
#head .wrapper .nav:first-child a{
    background: #1f87e8;
    color: #ffffff;
    color: black;
    
}
#head .wrapper .nav a:hover{
    background: #1f87e8;
    color: #ffffff;
}
#head .wrapper .nav ul{
    display: none;
}
#head .wrapper .nav .on:hover ul{
    display: block;
    background: #076ce0;
}
#head .wrapper span{
    position: absolute;
    right: 20px;
    top: 36px;
}
#head .wrapper .nav ul{
    padding-bottom: 30px;
}
#head .wrapper .nav ul li{
    width: 104px;
    height: 35px;
}
/* 中间内容 */




/* 底部 */
#foot{
    width: 100%;
    height: 270px;
    background: #212832;
}
#foot .wrapper{
    width: 1200px;
    display: flex;
    justify-content: space-around;
    margin: 0px auto;
}
#foot .wrapper img{
    width: 60px;
    height: 60px;
    margin-top: 95px;
}
#foot .wrapper span{
    display: block;
    width: 240px;
    margin-top: 110px;
    color: #ffffff;
}
#foot .wrapper p{
    display: block;
    width: 240px;
    margin-top: 115px;
    color: #ffffff;
}
#foot .footer{
    margin-top: 10px;
}
#foot .footer p{
    text-align: center;
    color: #8b939e;
    font-size: 14px;
}
#foot .footer p a{
    color: #8b939e;
    font-size: 14px;
}
#foot .footer p a:hover{
    color: #ffffff;
}
#foot hr{
    border-color: #3b424c;
}
/* 返回顶部 */
.return_top{
    right: 57px;
    bottom: 50px;
    opacity: 1;
    position: fixed;
    cursor: pointer;
    z-index: 20;
    width: 50px;
    height: 50px;
    transition: all .3s;
    background: url(../images/返回顶部图标.png) no-repeat center;
    display: block;
}